Elevator system

ABSTRACT

An elevator system having speed control apparatus providing first, second and third acceleration modes which provide progressively higher maximum speeds for an elevator car. Control circuitry associated with each landing to be served by the elevator car is successively enabled in response to the location and movement of the elevator car, with the number of floors from the last stop of the elevator car to the floor of the next stop being used to select one of the three acceleration modes. Protective apparatus responsive to the voltage across the armature circuit of the elevator drive motor is also provided which stops the elevator car when the rate of change of this voltage exceeds a predetermined magnitude, or the magnitude and polarity of the voltage indicates the elevator car is traveling at or above a predetermined speed in a direction opposite to the travel direction selected by the control circuitry.

United States Patent 1 Ostrander 51 Sept. 2, 1975 I ELEVATOR SYSTEMWilliam M. Ostrander. Hackensack, NJ.

[75] Inventor:

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh. Pa.

[22] Filed: Nov. 28, 1973 [21] Appl. No.: 419,759

Primary Examiner-Robert K. Schaefer Assistant Examiner-W. E. Duncanson,Jr. Attorney, Agent, or FirmD. R. Lackey SWITCHING CONTACTS CIRCUITDIRECT CONTACTS PATTERN PERV CONTROL 42 CALLS CAR POSITION SIGNALS D lRE CTION CONTACTS [57] ABSTRACT An elevator system having speed controlapparatus providing first, second and third acceleration modes whichprovide progressively higher maximum speeds for an elevator car. Controlcircuitry associated with each landing to be served by the elevator caris successively enabled in response to the location and movement of theelevator car. with the number of floors from the last stop of theelevator car to the floor of the next stop being used to select one ofthe three acceleration modes. Protective apparatus responsive to thevoltage across the armature circuit of the elevator drive motor is alsoprovided which stops the elevator car when the rate of change of thisvoltage exceeds a predetermined magnitude, or the magnitude and polarityof the voltage indicates the elevator car is traveling at or above apredetermined speed in a direction opposite to the travel directionselected by the control circuitry.

12 Claims, 8 Drawing Figures l6 i 26(DlRECT DRIVE) 62 5TH FLOOR 1- t "T4ULL |U| T ELI-5UL 4TH FLOOR 77/77 4TH FL 0 l qmslsu w owu) Y 5TH FLOORAL H.s. SLOWDOWN s2 3RD FLOOR W \F G 0 FLOOR i .SLCWDOWN T 4TH FLOOR BL7'-(H.s SLOWDOWN PATENTEU SEP 2 975 sumau s LONG RUN ZFLOOR RUN TlME-FIG. 2

AP los IFLOOR RUN ELEVATOR SYSTEM BACKGROUND OF THE INVENTION 1. Fieldof the Invention The invention relates in general to elevator systems.and more specifically to speed control and protective apparatus forelevator systems.

2. Description of the Prior Art It is conventional in elevator systemsto use a direct current motor for driving the traction sheave. A sourceof direct current voltage having a magnitude which is varied inaccordance with an error signal derived from signals representing theactual and desired speeds of the elevator car is connected to the drivemotor. With a maximum car speed of about 350 feet per minute. the directcurrent drive motor is usually connected to the traction sheave via areduction gear arrangement. such as a worm gear. With car speeds ofabout 400 feet per minute. and above. the direct current drive motor isusually directly connected to the traction sheave.

The floor selectors in common usage are those of the notching type. usedfor medium and slow speed applications. and those of the synchronoustype. used for high speed elevator applications. The notching selectoris commonly used with geared machines. and the synchronous selector iscommonly used with the gearless machines.

The notching selector moves in one floor steps. actuated by tape mountedcams or magnetic plates disposed in the hoistway and cooperativeswitches or inductors. respectively. carried by the elevator car. Thecarriage of the notching selector notches or steps as the car trav elsthrough the hoistway. until the selector notches into a landing or floorfor which a car call has been registered. or a hall call has beenregistered in the service direction of the elevator car. The presence ofsuch a hall call. or car call. enables the slowdown circuits associatedwith this landing. the car slows down according to a speed profileprovided by a speed pattern generator. and levels into the floor bylanding plates or cams located at the floor and cooperative landinginductors or switches carried by the elevator car. U.S. Pat. Nos.1.979.679 and 1.981.601 are illustrative of selectors of the notchingtype.

The synchronous selector is a scaled down or miniature version of theassociated elevator system. including a carriage arrangement which movesproportional to the travel of the elevator car. Separate carriagesystems are used for up and down travel and each carriage systemincludes two separately driven carriages. the synchronous and theadvanced carriages. The synchronous carriage moves proportional to themovement of the elevator car. The advanced carriage moves out ahead ofthe synchronous carriage for a distance equivalent to the slowdowndistance of the car. representing the advanced or effective carposition. A call for a floor at which the elevator car should stop.stops the advanced carriage at the location on the selector whichcorresponds to this floor. and the movement of the synchronous carriagetoward the stopped carriage aetuates contacts and control circuitry forcontrolling the slowdown of the elevator car. The car levels into thefloor via inductor plates disposed in the hoistway and cooperativelanding inductors carried by the car. U.S. Pat. Nos. 2.657.765 and3.160.232 are illustrative of selectors of the synchronous type.

The regulator systems used with the geared and gearless types ofelevator systems often differ substantially due to the differences incar speeds. With the slower geared elevator systems the regulator iscommonly of the type which utilizes a voltage produced across atcapacitor to develop a pattern or desired voltage for com parison with asignal responsive to actual car speed. to obtain an error signal forcontrolling the magnitude of the direct current voltage applied to thedirect current drive motor. This type of regulator will be referred to aregulator of the electronic type. U.S. Pat. Nos. 2.508.179. 2.620.898and 3.599.755 are directed to regulators of this type.

The high speed gearles systems. which operate with the synchronous typefloor selector may utilize a drag magnet regulator. in which actual carspeed and the pattern or desired speed are electromagnetically relatedto provide a resultant or error signal which controls the speed andposition of the elevator car. This type of regulator will be referred toas the electromagnetic regulator. U.S. Pat. Nos. 2.874.806 and 3.207.265describe drag magnet regulators and also inductor leveling of theelevator car at a landing.

The notching selector and electronic regulator used with the gearedelevator systems is less costly than the synchronous selector andelectromagnetic regulator used with the gearless elevator systems. andit would therefore be desirable to extend their usage into the lower endof the gearles speed range. such as gearless elevator systems whichoperate at about 500 feet per minute. This extension of notchingselectors and electronic regulators to higher speed elevator systems.however. must be made without a significant degradation in operatingperformance. such as floor-to-floor time. and the system should meet thesame high standards of safety now met by the presently used geared andgearless elevator control systems.

SUMMARY OF THE INVENTION Briefly. the present invention is a new andimproved elevator system which successfully extends the use of notchingtype selectors. electronic regulators. and switch type landing andleveling systems. to elevator systems which operate at a rated speed ashigh as 500 feet per minute. This higher speed usage of these operatingelements has been made without a significant reduction in floor-to-floortime. and with no compromise in operating safety.

More specifically. suitable floor-tofloor time has been achieved. evenfor one and two floor runs where the elevator ear does not reach maximumoperating speed before slowdown is initiated. by providing first. secondand third modes of operation which control acceleration of the elevatorcar to first. second and third progressively higher speeds. First andsecond slowdown indicators are provided in the hoistway for each floor.for each direction in which the floor may be approached by the elevatorcar. The first indicator initiates slowdown when the elevator car is inthe third operating mode. The second indicator is used during the thirdoperating mode as another slowdown point. and it also initiates slowdownwhen the elevator car is in the first operating mode. Counting meanscounts the notches or steps made by the selector from the last car stopto the next car stop. at least to distinguish and determine when theelevator car is making a two floor run. and the counting means isoperatively connected to prepare the elevator system for a two floor runwhen the notching means is notched or stepped into the second floor fromthe last stop of the elevator car. When the elevator car is making a twofloor run, the second operating mode is automatically selected. and thefirst slowdown indicator is prevented from initiating slowdown, as itdoes for runs which are longer than two floors. When the floor selectornotches into the second floor from the last car stop, timing means isstarted which continues acceleration of the elevator car for apredetermined period of time, with the elevator car passing the firstslowdown indicator without circuit effect. At the end of thispredetermined time, slowdown is initiated. The predetermined period oftime is adjustably selected to bring the car promptly to the desiredlanding, providing a floor-to-floor time which does not differsignificantly from those obtainable with electromagnetic regulators andsynchronous floor selectors.

New and improved safety arrangements are disclosed which monitor thevoltage across the armature circuit of the elevator drive motor, andwhich stop the elevator car when the polarity and magnitude of thisvoltage indicates the elevator car is moving above a predetermined speedin a direction opposite to the direction selected by the directioncircuits. The car is also stopped when the rate of change of thisvoltage reaches a predetermined magnitude, indicating acceleration ofthe elevator car above a desired magnitude. The protective circuitryalso monitors the car speed and the condition of the car doors, stoppingthe elevator car when the doors start to open when the speed of theelevator car is above a predetermined magnitude.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be betterunderstood, and further advantages and uses thereof more readilyapparent, when considered in view of the following detailed descriptionof exemplary embodiments, taken with accompanying drawings, in which:

FIG. 1 is a partially schematic and a partially block diagram of anelevator system which may be constructed according to the teachings ofthe invention;

FIG. 2 is a graph illustrating the operating characteristics of theelevator system of FIG. I when constructed according to the teachings ofthe invention;

FIG. 3 is a schematic diagram ofa speed pattern generator constructedaccording to the teachings of the invention;

FIGS. 4, 5 and 6 are schematic diagrams of control apparatus constructedaccording to the teachings of the invention. which apparatus cooperateswith the speed pattern generator shown in FIG. 3 to control the elevatorsystem shown in FIG. 1; and

FIGS. 7 and 8 are schematic diagrams of protective apparatus constructedaccording to the teachings of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsand FIG. I in particular, there is shown an elevator system 10 of thevariable voltage, gearless traction type which may be constructedaccording to the teachings of the invention. Elevator system 10 includesan elevator car 12 connected to a counterweight 14 via a suitable ropingarrangement 16 which is reeved over a traction sheave 18. The elevatorcar 12 is suspended in the hatch or (ill hoistway of a structure orbuilding to serve a plurality of landings or floor therein. of whichfive. the second through the six floors, are illustrated.

The traction sheave is driven by a direct current motor 20 having anarmature 22 and a field winding 24. The armature 22 is directlyconnected to the traction sheave 18 via a drive shaft 26. The fieldwinding 24 of the drive motor 20 is connected to a source 28 of constantdirect current potential.

A source of direct potential is provided for energizing the elevatordrive motor 20 to move the elevator car 12 in accordance with therequirements of the elevator system. This source may be amotor-generator set which includes a generator 30 having an armature 32driven at a substantially constant speed by a motor (not shown).Generator 30 also includes a shunt field winding 34, a regulating fieldwinding 36, and an interpole field winding 37.

The generator 30 has its armature 32 connected in a loop circuit withthe armature 22 of the elevator drive motor 20. The interpole fieldwinding 37 of the generator 30 is also connected in the loop circuit forenergization.

The shunt field winding 34 of the generator 30 is preferably connectedacross the terminals of the armature 32 of the generator 30 viaswitching contacts shown generally at 38, which are arranged toreversibly connect winding 34 to the generator armature 32.

The regulating field winding 36 accurately controls the output voltagedeveloped by generator 32, and thus accurately controls the speed of theelevator drive motor 20 and the position of the elevator car 12. Theregulating field winding 36 is energized from a power modulator 40,which is energized by a source 42 of alternating potential, via contactsfrom the direction circuits, shown generally at 44. Up and downdirection relays IR and 2R, which are part of the supervisory controlshown generally at 46, and which will be hereinafter described, controlthe direction of the elevator car, and contacts of these directionrelays connect the power modulator 44 to properly energize regulatingwinding 36 to achieve the desired travel direction of the elevator car12. The supervisory control 46 selects the travel direction in responseto registered car and hall calls, and the location of the floorsassociated therewith relative to the position of the elevator car 12. Asuitable power modulator using grid controlled rectifiers ofgaseous-discharge type (thyratrons) are disclosed in US. Pat. Nos.2,508,179 and 2,620,898, while a suitable modulator using solid statecomponents is disclosed in US. Pat. No. 3,470,434, all of which areassigned to the same assignee as the present application.

The power modulator is controlled by an error signal derived bycomparing a signal from a pattern generator 48, which represents thedesired speed of the elevator car, with a feedback signal responsive tothe actual speed of the elevator car. Pattern generator 48 receives itsenergy from a source 49 of alternating potential. A tachometer generator50 driven by the motor armature 22, as indicated by broken line 52, isthe preferred arrangement for obtaining the feedback signal because itprovides continuous direct measurement of the speed of the elevatordrive motor. First and second derivative damping, as well as filteringof the output signal from tachometer generator 50 is provided by acircuit shown generally at 54, and this compensated tachomcter signal issummed in opposition to the signal from the pattern generator 48 in acircuit 56 which includes appropriate contacts from the direction relaysIR and 2R, which will be hereinafter described. The resultant signalobtained in circuit 56, which uses contacts of the direction relays toobtain a signal responsive to the difference between the actual anddesired car speeds. i.c.. error signal, is applied to the powermodulator to control the magnitude of the direct current potentialapplied to the regulating field winding 36 via the direction contacts44. As disclosed in U.S. Pat. No. 3,620,898, first derivative dampingmay be obtained by differentiating the voltage across the armature 22 ofthe motor 20, while second derivative damping may be obtained bydifferentiating the voltage across the interpole field winding 37.

The supervisory control 46 additionally includes a floor selector of thenotching type, such as described in U.S. Pat. No. 1,979,679, which isstepped or notched in response to indicators AL and BL disposed in thehoistway. These indicators may be cams for operating switches. carriedby the car, magnetic plates for operating inductor relays carried by thecar, or permanent magnets for operating magnetically responsiveswitches. such as reed switches, carried by the elevator car. Theswitches, inductor relays, or Red switches are mounted on the elevatorcar 12 in a control panel shown generally at 60. The indicators AL andBL are disposed in different vertical lanes in the hoistway in order toactuate two notching switches AL and BL al ternately from floor-to-floorand thus prevent contact bounce from falsely notching the floorselector.

Slowdown of the elevator car is responsive to indicators SUL and 4ULdisposed in the hoistway for each floor which may be approached when thecar is traveling upwardly, and in response to indicators SDL and 4DL(not shown) disposed in the hoistway for each floor which may beapproached when the car is traveling downwardly. As will be hereinafterexplained, indicators SUL and SDL are high speed slowdown indicators.while indicators 4UL and 4DL are medium or intermediate speed slowdownindicators. The SUL and SDL indicators for a given floor are disposedabout 12.5 feet from its associated floor, when the maximum rate ofspeed of the elevator car is about 500 feet per minute, and the 4UL and4DL indicators are disposed about 4.5 feet from the associated floor toprovide another slowdown point when the car is slowing from the 500 feetper minute maximum speed. As indicated in FIG. 1, it is possible for themedium speed slowdown indicator, such as 4UL, for one floor to bebetween the high and medium speed slowdown indicators, such as SUL and4UL. associated with an adjacent floor. A control arrangement forignoring the intervening medium speed slowdown indicator will behereinafter described.

Leveling of the elevator car 12 at a landing may be performed byleveling cams 62 associated with each floor or landing, which may bemounted on a suitable tape 64 which extends the length of the hoistway.Switches lDL and lUL carried by the elevator car coperate with a cam 62when the elevator car arrives in the leveling zone for stopping at theassociated landing. and will perform releveling of the elevator carshould the car overshoot or move away from the landing due to ropestretch. Actuation of both switches lDL and lUL indicates the elevatorcar is within i0.5 inch of floor level, while movement of the elevatorcar up or down from this position closes switch lDL or lUL,respectively, to energize the re-leveling control in the directionrequired to re-level the car 12 with the floor level.

FIG. 2 is a graph illustrating speed profile patterns of an elevator carusing new and improved control circuitry constructed according to theteachings of the invention. Car speed is plotted on the ordinate versustime which is on the abcissa. When the elevator car is making a onefloor run, the car accelerates along curve portion until reaching apredetermined medium speed, indicated by curve portion 72. At about 4.5feet from the floor, i.e., the proper distance to slow the car from theselected medium speed according to a predetermined decelerationschedule, which distance is indicated by hoistway indicators 4UL or 4DL,the car decelerates smoothly into the leveling zone along curve portion74.

On a run of more than 2 floors, the elevator car accelerates along curveportion 70 until reaching the rated speed of the elevator system, suchas 500 feet per minute, respresented by curve portion 76. At about 12.5feet from the floor at which the elevator car is to stop, as indicatedby the indicator SUL or SDL. associ ated with this floor, the elevatorcar decelerates smoothly into the leveling zone along curve portion 78.

The elevator ear cannot reach a rated maximum speed of 500 feet perminute, represented by curve portion 76., on a two floor run. Thus. whenthe high speed slowdown indicator SUL or SDL is reached the cardecelerates along curve portion to the one floor run speed. representedby curve portion 72', and upon reaching the medium speed slowdownindicator 4UL or 4DL associated with this floor, it decelerates into thefloor along curve portion 82. This slowdown profile is undersirable asit unduly lengthens the time required to make a two floor run.

The present invention counts the notches or steps of the notchingselector from the last Stop of the elevator car, and when the circuitryassociated with the floor associated with the second notch from the laststop indicates the elevator car may be making a two floor run, a thirdoperating mode is automatically provided when the circuitry associatedwith this second landing from the last stop indicates the elevator carshould stop at this landing. The third operating mode ignores the highspeed slowdown indicator 5UL or SDL, maintaining the acceleration of thecar along curve portion 70 for a predetermined period of time selectedto enable the car to reach a speed which will permit the desired smoothslowdown profile into the leveling zone of the floor, and provide thedesired floor-to-floor time. The broken curve 84 indicates a modifiedtwo floor run obtained by following the teachings of the invention.

As an aid to understanding the drawings, the relays are identified asfollow s:

A Brake Monitor Relay ACC Acceleration Relay ADT MonitorRelay-Acceleration CPR Protective Relay (JR-4 Pattern VoltageRelay-Mediuni Speed GR4B Pattern Voltage Relay GR4T Pattern Voltage TimeRelay CR6 Pattern Voltage Relay-High Speed GR6T Pattern Voltage TimeRelay LD Leveling Relay LU Leveling Relay M Running Relay N NotchingRelay NA Notching Relay for Alternate Floors NB Notehing Relay forIntervening Floors OVD Monitor Relay Motor Armature Current for DownTravel OVU Monitor Relay Monitor Armature Current for Up Travel SAOlSelector Relay Associated With Lower Terminal SAOT Selector RelayAssociated with Upper Terminal X Relay Counts First Notch of Selector YRelay Counts Second Notch of Selector YT Two Floor Run Time Relay Z TwoFloor Run Relay 1R Up Direction Relay 1C Up Direction Relay 2R DownDirection Relay 2C Down Direction Relay 6R Potential Switch 6P PotentialSwitch 22R Running Relay 23R Running Relay 29R Safety Circuit Relay 32RRunning Relay 34R Master Slowdown Relay 38R Car Call Slowdown Relay 39RNotching Relay 39A Notching Relay With Delayed Dropout 40R Car DoorRelay R Master Car Door Relay R Overspeed Relay H Hand Control Relay RRunning Relay T Door Non-interference Time Relay C Master Call Relay 80DAttendant Relay Down 80U Attendant Relay Up 81D Down Travel DirectionRelay 8lU Up Travel Direction Relay 81R Travel Direction Relay 438RCorridor Call Slowdown Relay Contacts associated with these relays areidentified by hyphenated reference characters, with the associated relayidentification to the left of the hyphen. and the contact identificationto the right of the hyphen. The relay contacts are shown in their normalposition when the relay is dc-energized.

FIG. 3 is a schematic diagram of a new and improved pattern generator 48which provides first, second and third speed patterns for runs of one,two, and more than two floors, respectively. When the elevator car ismaking a one floor run, the speed pattern generator 48 provides the onefloor run pattern shown in FIG. 2. If the circuits of the landing orfloor associated with the first notch of the floor selector followingthe stop of the elevator car have not been set to request the elevatorcar to stop but the circuits of the landing associated with the secondnotch following the last stop of the elevator car are set to request thecar to stop. the speed pattern generator 48 provides the speed patternillustrated with the broken line in FIG. 2. Counting means counts thenumber of notches following the last stop of the elevator car, and onthe second notching of the floor selector the pattern generator preparesfor a two floor run immediately, whether or not the elevator car is tostop at this second floor after the last stop. If a stop is not made forthis floor. the floor selector automatically provides a speed profileassociated with a long run.

More specifically. the desired speed pattern signal is provided acrossan energy storage device, such as eapacitor 100, which includesterminals 101 and 103 connected to its upper and lower plates,respectively. The acceleration portion of the speed pattern profilesshown in FIG, 2 is provided by controlling the rate at which capacitoris charged. The deceleration portion of the speed pattern profiles isprovided by controlling the rate at which capacitor 100 is discharged. Asource of direct current potential, provided by source 49 of alternatingpotential, full-wave bridge rectifier 102, and filter capacitor 104, hasan output terminal 107 connected to selector arm AP of an adjustableresistor 106, and its other output terminal 113 is connected to terminal103 of capacitor 100 via a resistor 120. Resistor is part of a voltagedivider network, as will be hereinafter described. A regulated orconstant source of direct current potential, as provided by resistor 108and Zener diode 110, has its output terminals 111 and 113 connectedacross a voltage divider network which includes serially connectedresistors 112, 114, 116, 118, and 120. Resistors 114, 116, and 118 areadjustable, having selector arms IS, 225 and LS. respectively. Resistors122 and 124 are serially connected across resistors 112 and 114, withresistor 122 being of the adjustable type, having a selector arm HS.

Capacitor 100 has its terminal 103 directly connected to junction 126between resistors 118 and 120, and its terminal 101 is selectivelyconnected to provide the desired charging and discharging rates at theappropriate times during a one floor, a two floor, and a longer run. ofthe elevator car.

When the contacts of the door interlock relays close, which are showngenerally at 128, indicating the elevator car and hatch doors areclosed, and the acceleration relay ACC picks up to close its contactsACC-1, capacitor 100 starts to charge along curve portion 70 shown inFIG. 2. The rate at which capacitor 100 charges, and thus the basicacceleration rate, is selected by arm AP of resistor 106.

If a one floor run is to be made. the medium speed relay GR4 will bepicked up, and both the high speed run relay GR6 and the two floor runrelay Z will be denergized. Thus, a circuit will be established fromterminal 101 of capactir 100 to selector arm IS of resistor 114 throughcontacts ACC-1- the door interlock contacts 128, contacts 2-2, GR6-2,and GR4-1, and diode 130. Diode 130 is poled to clamp the voltage acrosscapacitor 100 to the value selected by arm IS of resistor 114. Thisvoltage represents the medium or intermediate speed illustrated by curveportion 72 in FIG. 2. When relay GR4 drops in response to the elevatorcar passing indicator 4UL or indicator 4DL in the hoistway, theacceleration relay ACC also drops and capacitor 100 discharges to alower voltage setting selected by contact ACC-3 and additional contactswhich will be hereinafter described.

Ifa two floor run is to be made. both the medium and high speed relaysCR4 and GR6 will pick up. This arrangement completes a circuit fromterminal 101 of ca pacitor 100 to arm HS of resistor 122 via contactACC- 1, the door interlock contacts 128. contacts GR6-l, and diode 132.Diode 132 is poled to clamp the voltage across capacitor 100 to thesetting selected by arm HS of resistor 122. which setting determines themaximum speed to which the elevator car will be accelerated. such as 500feet per minute. On a two floor run. however, there is not enough timeto accelerate the car to a maximum speed of 500 feet per minute. withthe high speed slowdown indicator UL or SDL dropping the high speedrelay GR6 shortly after the car exceeds the speed magnitude for a onefloor run. Without the two floor run relay Z. the car would decelerateto the one floor run speed illustrated by curve portion 72 in FIG. 2. asthe dropping of relay GR6 drops the acceleration relay ACC. contactsACC-Z and ACC-3 close and the circuit from arm 18 of resistor 114 toterminal 101 is completed via a diode 134. and contacts GR4-2, ACC-2 andACC-3. Capacitor 100 discharges through resistor 120. and throughadjustable resistors 136 and 138 until the voltage across its terminalsreaches the voltage setting of selector arm of resistor 114. Resistors136 and 138 are of the adjustable type having selector arms D and DT.respectively. Terminal 113 of the power supply is connected directly toone side of resistor 136. and also to its selector arm D via normallyclosed contact GR4-4 relay GR4. The other side of resistor 136 isconnected to arm DT of resistor 138. One side of resistor 138 isconnected to terminal 101 of capacitor 100 via normally closed contactACC-3.

The two floor run relay Z. however. is energized when the selectornotches into the second landing from the last stop of the elevator car.and it is energized for a predetermined period of time following thenotching of the selector into the second floor. Thus. when the elevatorcar is to stop at the second landing from the last stop of the elevatorcar. relay GR6 drops when the car passes hatch indicator SUL or SDL.which for a maximum car speed of 500 feet per minute is disposed about12.5 feet from the floor at which the car is to land. However. thedropping of relay GR6 has no immediate circuit affect. as contacts Z-lof the energized Z relay shunt the now open GR6-1 contacts to maintainacceleration of the car along curve portion 70 shown in FlG. 2. ContactZ-2 in the medium speed clamping circuit is open at this point in time.Contact Z-3 of the two floor run relay. which contact is shown in FIG.4, maintains cncrgization of the acceleration relay ACC despite theopening of contact GR6-4. When the predetermined period of time forextending the acceleration period of the elevator car expires, relay Zdrops. the acceleration relay ACC drops. and capacitor 100 dischargestoward the voltage level selected by arm 15 of resistor 114. by thecircuit hereinbefore described. This time period for energizing the twofloor run relay Z is preferably selected to enable the elevator car toreach the speed setting of arm lS at about the same time. or justshortly before. the car reaches hatch indicator 4UL or 4DL. dependingupon car direction. which indicators are located about 4.5 feet fromtheir associated floor for a 500 foot per minute maximum car speedelevator system. Thus. the deceleration curve for a two floor run.illustrated by the broken curve in FIG. 2, will be smooth. orsubstantially smooth. having at the most a slight flattening as itreaches curve portion 72' of FIG. 2. and it substantially shortens thetime for a two floor run. compared with the time required for a twofloor run if the car were to start decelerating from the high speedslowdown indicator SUL. or indicator SDL. On a run longer than twofloors. the two floor run relay Z will pick up and drop out withoutcircuit affect. as the indicator 5UL or 5DL for the second floor fromthe last stop will not drop out the speed pattern relay GR6. Theelevator car continues to accelerate to the maximum speed determined bythe setting of arm HS of resistor 122. which is indicated by curveportion 76 in FIG. 2. From this maximum speed, the slowdown is promptand smooth along curve portion 78 shown in FIG. 2. being initiated whenthe elevator car is 12.5 feet from the floor of the stop by hatchindicator SUL or indicator SDL.

When the elevator car is 4.5 feet from the floor at which it is to stop.relay GR4 drops due to the hatch indicator 4UL or indicator 4DL. contactGR4-2 opens to open the circuit from terminal 101 of capacitor to thespeed setting arm 1S. and contact GR4-3 closes to connect terminal 101of capacitor 100 to arm 225 of resistor 116 via contacts ACC-3. GR4-3.GR4T-l. 34R-1. 22R-1. and diode 140. The function of relays GR4T. 34Rand 22R will be described when a complete system operation is set forth.The capacitor 100. therefore. discharges from the voltage setting of arm[5 of resistor 114 to the voltage selected by arm 228 of resis tor 116.Capacitor 100 discharges through resistors 120, 136 and 138. but at ahigher rate than when decelerating to the 18 speed setting. as contactGR4-4 of relay GR4 is now closed. to shunt a portion of resistor 136 viaits selector arm D.

When the elevator car reaches the leveling zone. which is about 3 inchesfrom the floor as determined by the length of the cams 62 shown in FIG.1, one of the leveling switches lDL or lUL will open to drop itsassociated leveling relay LD or LU. and when either of the levelingrelays LD or LU drops out. relay 22R drops to open its contacts 22R-l inthe 22S selector arm circuit of resistor 116. Capacitor 100 thendischarges to the setting of arm LS of resistor 118, with terminal 101of capacitor 100 being connected to arm LS via diode 142. and contactsGR4-3 and ACC-3. Arm LS selects the landing speed in the leveling zone.

When the elevator car is within i0.5 inch of the floor. both levelingswitches 1UL and 1DL will be open by cam 62, both leveling relays LU andLD will be denergized. and relay 6P drops to close its contact 6P-1.

Contact 6P-1 slows the elevator car to a stop by completing a circuitfrom selector arm LS of resistor 118 to terminal 103 of capacitor 100which includes an adjustable resistor 144 having a selector arm LSS.contacts 6P-l and 23R-1. Arm LS of resistor 118 is connected to arm LSSof resistor 144, and one side of resistor 144 is connected to terminal103 of capacitor 100 via contacts 6P-1 and 23R-1. The voltage acrosscapacitor 100 is thus reduced from that between arm LS and terminal 113of the power supply. to that appearing between arms LS and LSS andjunction 126 of the voltage divider. which voltage brings the car to astop and the brake is then applied.

In describing the operation of the elevator system. FIGS. 1 through 6will be referred to. lt will be assumed that the elevator car is parkedat a floor with the brake applied. and with the doors open. The masterslowdown relay 34R shown in FIG. 6 will be energized through thenormally closed contact 45R-1 of the master door relay 45R (not shown),which is tie-energized until the doors are signaled to close. The 34Rrelay is II II energized while the doors are open to keep levelingcffective. Contacts 80U-I and SOD-I are associated with up and downrelays (not shown) for attendant service. either of which will drop 34Rshould attendant wish to leave immediately after a stop. On automaticoperation, the holding circuit of master slowdown relay 34R is brokenwhen relay 70T drops. With master slowdown relay 34R de-energized, bothleveling relays LU and LD are energized via contacts 34R-8 and 34R-9,respectively, even though the elevator car is at a floor and switchesIUL and IDL are held in their open position by cam 62, as illustrated inFIG. 1. With the brake applied, the brake monitor relay A (not shown) isenergized, with the door non-interference time expired, thenon-interference relay 70T (not shown) is deenergized, its contact 70T-lin the circuit of the master call relay 80C (FIG. 6) is closed, and itscontact 70T-2 in the holding circuit of master slowdown relay 34R isopen. Relay YT (FIG. 4) is energized, and relay 22R (FIG. 6) isenergized via the closed contacts LU-S, LD-S and the closed contacts ofthe door interlocks, shown generally at 150.

Assume now that a travel direction for the elevator car is established,such as manually by an attendant operated car switch 80U or 80D, orautomatically by circuits which compare the floor destination of a carcall, or the floor at which a hall call is registered, with the locationof the elevaror car. If the car direction selected by the operator, orautomatic circuits, is up, the up direction relay SIU and masterdirection relay 81R are both picked up, and if the direction is down.the down direction relay 81D and the master direction relay 81R arepicked up. These direction relays are not shown since their operationsare well known in the art.

When a car direction is established, indicated by relay 81R picking up,its contact SIR-l in FIG. 6 closes to pick up the master call relay 80C.If the direction selected was up, contact SOC-I in FIG. plus contactSSR-l, which is closed when the ovcrspeed relay 55R (not shown) isenergized. indicating there is no overspced condition, plus contactsSlU-l, LU-l, 2R-I and 2C-l pick up the up direction relay 1C, providedthat the upper travel direction limit switch UL is closed, indicatingthat the car is not already at the uppermost landing served by car. Itscontacts IC-I and 1C-2 close to pick up relay 6P via either contactsLU-4 or LD-3, which are both closed, and it also picks up relay 6R. Whenrelay 6P picks up, its contact ()P-l opens and capacitor 100 chargesslightly to the voltage appearing at arm LS of resistor 118 to providean initial pattern voltage sufficient to hold the car when the brake islifted. Relay 6R closes its contact 6R-2 and the up direction relay IRpicks up. Contact IR-Z of the up direction relay 1R located in FIG. 5picks up relay 65R via the now closed contact SOC-2 of the master callrelay 80C. Contact 65R-2 closes to seal in around contact 80C-2. Relay32R also picks up. Contact lR-3 in FIG. 6 picks up relay GR4B throughthe closed contact 34R-2 of master slowdown relay, or through the closedmedium speed slowdown switch 4UL which cooperates with the 4UL indicatordisposed in the hatch, through contact 34R-4, through the now closedcontact 65R-3 of the running relay 65R, and through closed doorinterlocks 150.

Contact GR4B-2 closes to enable relay (3R4. Contacts GR4B-3 and GR4B-4close in the LU and LD relay circuits, respectively. Contact GR4B-Icloses to pick up relay 23R in FIG. 5.

When the directional relay 1R picks up, the brake is released and thebrake monitor relay A drops, opening it contact A-Z in FIG. 6, andtiming relay GR4T drops after a delay to close its contact GRdT-Z andpick up relay GR4.

It will first be assumed that there are no car or corridor calls for thefirst two floors adjacent the elevator car, and thus the elevator carwill make a run of more than two floors, which is referred to as a longrun. When relay GR4 picks up for more than a one floor run, relay GR6also picks up. Contact GR6-4 in FIG. 4 closes to pick up theacceleration relay ACC, and contact GR6-3 closes to pick up runningrelay M.

When the running relay R picks up it closes its contact 65R-1 in FIG. 4to prepare the two floor run portion of the supervisory control 46.However, since this portion of the circuit has no affect on theoperation of the elevator system when the elevator car is making a longrun, its description will be delayed until the two floor run isdescribed.

When relays GR6 and ACC pick up, contacts GR6-I and ACC-I close, and thepattern generator 48 shown in FIG. 3 provides a pattern whichaccelerates the elevator car along curve portion of FIG. 2 to themaximum car speed, which is selected by arm HS of resistor I22. Thefirst notching of the selector occurs before the car moves away from thefloor, and the second and subsequent notchings of the selector are inresponse to the AL and BL cams in the hoistway. When the elevator carpasses notching indicator AL in the hatch, it momentarily drops a relayNA (not shown), and when the elevator car passes notching indicator BLin the hatch it momentarily drops a relay NB (now shown). Contacts NA-Zand NB-2 of these two notching relays, which contacts are shown in FIG.4, drop the master notching relay N each time either notching relay NAor notching relay NB notches to the next floor. During the shortnotching period, indicated by the de-energized condition of relay N,normally closed contacts of relay N pick up notching relays 39R and 39A(not shown). Notching relay 39R drops when notching relay N picks upfollowing the completion of the notching of the selector, and notchingrelay 39A drops after a short delay following the picking up of relay N.Thus, contacts N-2 and 39A-I of notching relays N and 39A in FIG. 6 areboth closed for a short period of time following a notching or steppingof the floor selector as it notches into the next floor. Contact 23R-3is closed, which occurred when relay GR E'B picked up. If there is areason to stop at the floor associated with this new notch of the floorselector, the master slowdown relay 34R will pick up. For example, relay3 3R will pick up if: (a) contact 438R-I is closed, indicating there isa hall call for this floor, (b) contact 38R-I are closed indicating acar call for this floor, (c) contacts 2C-4 and SID-2 are closed,indicating the car is traveling downwardly and there are no calls aheadof the car. (d) contacts 1C-4 and SlU-Z are closed indicating the cartraveling upwardly and there are no calls ahead, or (e) either contactsSAOT-I or SAOl-l are closed. indicating that the selected floor is theupper or lower terminal floor, respectively.

When master slowdown relay 34R picks up, its contact 34R-I in FIG. 3prepares the 22S slowdown circuit of the pattern generator, its contacts34R2, 34R-3, 34R-5 and 34414 in FIG. 6 render the slowdown switches 4UL.4DL, 34Rl in FIG. 3 prepares the 22S slowdown circuit of the patterngenerator. its contacts 34R-2, 34R-3. 34R-5 and 34R-6 in FIG. 6 renderthe slowdown switches 4UL. 4DL. SUL and SDL. respectively, effective.its contacts 34R-4 and 34R-7 in FIG. 6 open to prepare relays GR4, GR4Band GR6 for drop out, its contacts 34R-8 and 34R-9 prepare levelingrelays LU and LD for dropout. and its contact 34R- 10 seals itselfinthrough the closed contacts 65R-4 and 70T-2 of the running andnon-interference time relays 65R and 70T, respectively.

When the elevator car reaches the high speed slowdown indicator SUL inthe hatch when going upwardly, or the SDL hatch indicator when goingdownwardly, the switch carried by the elevator car with the sanereference characters in FIG. 6 opens to drop relay GR6. Timing relayGR6T starts to time out when contact GR6-6 opens, with the time beinglong enough for the elevator car to pass an intervening 4UL or 4DLindicator for the floor preceding the one which the elevator car is tostop. For example, as shown in FIG. I. if the elevator car is goingupwardly and the SUL indicator for the 4th floor opens switch SUL, relayGR6T will remain energized, shunting switches 4UL and 4DL with itsclosed contacts GR6T-I and GR6T-2 until the indicator 4UL associatedwith the third floor is passed. When relay GR6T times out and drops, itprepares the 4UL switch to be actuated by the 4UL indicator associatedwith the fourth floor.

When relay GR6 drops at the high speed slowdown indicator SUL, or SDL,its contact GR6-4 in FIG. 4 opens to drop the acceleration relay ACC.The running relay M does not drop when contact GR6-3 opens. as therunning relay M seals itself in via its contact M-l.

When the acceleration relay ACC drops, contacts ACC-l and ACC-3 in thepattern generator 48 of FIG. 3 open and close, respectively, todecelerate the car towards the voltage selected by arm IS of resistor114 of the pattern generator. When the elevator car reaches the 4ULindicator in the hoistway, the switch 4UL shown in FIG. 6 opens to droprelays GR4 and GR4B. Contact GR4-2 opens and contact GR4-3 closes todischarge capacitor 100 towards the voltage selected by arm 225 ofresistor I16. Assume the elevator car is traveling upwardly. When itreaches cam 62, about 3 inches from the floor level. switch lDL opensand leveling relay LD drops. Contact LD-S of relay LD in FIGv 6 opens todrop relay 22R. and relay 80C drops via the contact 22R-5 in the holdingcircuit of relay 80C. Contact 22R-l of relay 22R in the patterngenerator 48 of FIG. 3 opens to discharge capacitor 100 towards thevoltage selected by the arm LS of resistor 118. At onehalf inch from thefloor level cam 62 opens switch lUL (FIG. 6) and leveling relay LUdrops. Contacts LU-4 and LD-3 in FIG. 5 are now both open. which dropsrelay 6P to start the brake setting. The pattern is now controlled bythe LSS potentiometer, which is set for zero Speed. The car stops beforethe brake sets. When the brake is fully set, brake monitor relay A picksup. Its contact A-l in FIG. 5 opens and relays 1R, 1C and 6R all drop.When the directional relay lR drops, contacts 1R-2 in FIG. 5 open andrelays 23R. 32R and 65R all drop out. Relay 70T starts the door opennoninterference time and then times out and drops.

If the elevator car should overshoot the landing while going in the updirection. switch IDL will go off of cam 62 and close its contacts.picking up leveling relay LD.

As shown in FIG. 5, contact LD-4 will close and pick up the downdirection relay 2C via contact LU-2 of the up leveling relay LU, contact22R-4 of running relay 22R, and contact CPR-l of a protective relay CPR.5 which will be hereinafter described. Relays 2R. P and 6P all pick up.the brake is picked up. the brake monitor relay A drops, and the carlevels back to the landing via the voltage at arm LS of resistor 118.When switch IDL opens. relays LD. 2R, 2C. P and 6P, all drop out, thebrake is applied. and the brake monitor relay A is energized. It will beobvious from the drawings that if the car is traveling downwardly andovershoots the floor, how the elevator car re-levels back to the floor,using the switch lUL and the up leveling relay LU.

On a two floor run, relay N of FIG. 4 drops out on the first notching ofthe selector following a stop of the car, which occurs while the car ispreparing to leave the landing, closing its contact N-l and notchingrelay 39R (not shown) picks up to close its contact 39R-l. Thus. on thefirst notch or step of the floor selector. relay X is energized.counting to one. Contact X-l closes to seal in relay X. and contact X-2closes to prepare the circuit of relay Y. Upon the next notching of thefloor selector. responsive to passing an indicator in the hatch.contacts NA-I or NB-l of the notching relays close to energize relay Y,counting to two. Relay Y seals itself in via contact Y-I. and it opensits contact Y-2 to start the timed dropout of timing relay YT. It alsocloses its contact Y-3 to energize the two floor run relay Z for thetiming period of relay YT. When relay YT times out and drops, relay Z isde-energized. The circuit effect of relay Z during a two floor run washereinbeforc described when the pattern generator 48 was described, withits contact Z-I bypassing contact GR6-l to prevent the elevator car frominitiating slowdown when it passes the SUL or SDL hatch indicator. itopens the medium speed circuit IS via its contact Z-2, and it maintainsthe energization of acceleration relay ACC via its contact Z-3. Thetiming period of relay YT is selected to continue the speed patternalong the acceleration curve 70 until reaching a speed magnitude atwhich slowdown will be smooth and will bring the cl evator car into thedesired floor without undue delay.

On a one floor run, when the floor selector notches into the flooradjacent the last stop of the elevator car, which occurs as the carprepares to leave the floor. the request to stop associated with thisnotch picks up the master slowdown relay 34R. Its contact 34R-7 in FIG.6 opens and relay GR6 does not pick up when relay GR4 picks up. Thus,relay M does not pick up. When relay GR4 picks up, the accelerationrelay ACC picks up via contacts GR4-5 and M-2. and the car acceleratesto the speed setting of arm IS of resistor 114 of the speed patterngenerator 48.

FIGS. 7 and 8 are schematic diagrams of protective apparatus constructedaccording to the teachings of the invention. FIG. 7 is a schematicdiagram ofa protective circuit 160, which is also illustrated in blockform in FIG. 1, which circuit is powered by a source 162 of alternatingpotential. Protective circuit 160 is connected to the portion of theloop circuit of the elevator drive motor which is shown generally withinthe dashed rectangle I64 in FIG. 7. Circuit 164 includes the motorarmature winding 22 and the generator interpole field winding 37.

A voltage divider, including resistors 166 and 168, is connected acrossthe armature circuit 164, with resistor 168 being an adjustable resistorhaving a selector arm 170. The magnitude and polarity of the voltageappearing between arm 170 and junction 172 is responsive to therotational speed and rotational direction of motor 20. A transformer 174having a primary winding 176 connected to source 162, includes twosecondary windings 178 and 180 connected to full-wave bridge rcctifiers182 and 184, respectively. The direct current output voltage of bridgerectifier 182 is filtered via capacitor 192 and resistor 194, and thedirect current output voltage of bridge rectifier 184 is filtered bycapacitor 196 and resistor 198.

The positive output terminal of bridge rectifier 182 is connected to thenegative output terminal of bridge rectifier 184 at junction 188, andthis junction is connected to the junction 172 between the interpolefield winding 37 and armature 22 of the drive motor 20. The negativeoutput terminal 186 of bridge rectifier 182 is connected to selector arm170 of resistor 168 via relay OVD and resistor 216, and the positiveoutput terminal 190 of bridge rectifier 184 is connected to selector arm170 via relay OVU and resistor 218. Normally closed contact GR4-7 ofrelay CR4 and normally open contact 22R-2 of relay 22R are seriallyconnected across resistor 216, while normally closed contact GR4-8 andnormally open contact 22R-3 are connected across resistor 218.

When the drive motor is not rotating, the elevator car is stationary ata landing, both relays OVU and OVD are picked up due to the outputvoltage of the serially connected bridge rcctifiers 182 and 184. Whenthe motor 20 starts to rotate in a direction to move the elevator car inan upward direction, the voltage at selector arm 170 becomesincreasingly more positive as the motor speed increases, until a motorspeed is reached which generates a voltage sufficient to reduce thevoltage across relay OVU to the point where it will drop out. ContactGR4-8 is open during this period of time, and contact 22R-3 is closed.The positive voltage at selector arm 170 has no adverse affect on thecondition of relay OVD, and it remains energized. Upon slowdown. whenrelay GR4 drops out at 4.5 feet from the floor, resistor 218 is shuntedto enable relay OVU to pick up at substantially the same output volt agefrom motor 20 at which it dropped out.

In a similar manner, if drive motor 20 starts to rotate in a directionto lower the elevator car, the voltage at junction 172 becomesincreasingly more positive as the elevator drive motor increases inspeed until relay OVD drops out. Relay OVU remains energized.

Contacts GR4-7 are open and contacts 22R-2 are closed during theacceleration period. When the motor decelerates, Contact GR4-7 opens 4.5feet from the floor and relay OVD will pick up at substantially the samemotor speed at which it dropped out.

Protective circuit 160 additionally includes a circuit 200 whichmonitors the rate of change of motor voltage, and thus monitors theacceleration rate of the motor and elevator car. A capacitor 202 isconnected from one side of the motor armature 22, at junction 171, toone end of a two branch parallel circuit 201 which includes seriallyconnected resistors 204 and 206 in one branch, and serially connectedcapacitor 212 and resistor 214 in the other branch. Resistor 204 isadjustable, having a selector arm 208. The remaining side of theparallel circuit 201 is connected to the remaining side of the motorarmature 22 atjunction 172. A bridge rectifier 210 has its inputterminals connected across capacitor 212, and a monitoring relay ADT isconnected across the output terminals of the bridge rectifier 210.

Capacitor 202 blocks current flow from the motor armature circuit whenthe voltage across the armature is static, and it passes current indirect proportion to the rate of change of motor armature voltage. Thus,during acceleration of the drive motor and'elevator car, capacitor 212charges to a magnitude proportional to the rate of change of armaturevoltage. If the rate of change of armature voltage exceeds apredetermined magnitude, which is selected by adjustment of resistor204, relay ADT will pick up.

P10. 8 is a schematic diagram which illustrates how contacts of relaysOVD, OVU and ADT are utilized to provide new and improved protectivefunctions. A pretective relay CPR is connected between busses L+ and Lvia a plurality of contacts and switches which monitor various functionsof the elevator system. Relay CPR has a normally open contact CPR-1 inFIG. 5 connected such that the elevator car will not run should relayCPR become deenergized.

Relay CPR is connected serially with belt switches, shown generally at230, which are closed as long as the belts which they are associatedwith are not broken, normally open contacts OVD-1 and OVU-l of the motorvoltage monitoring relays, normally closed contact ADT-l of theacceleration monitoring relay, and its own normally open contact CPR-2.A normally open pushbutton 232 is connected across contact CPR- 2.Normally open contacts 2R-5 and lR-5 of the up and down direction relays2R and IR, respectively, are serially connected across contacts OVD-land OVU-1. Normally open contacts 40R-l of the door monitoring relay 40Rand normally closed contact H-1 of the hand control relay 60H areserially connected from the junction 234 between contacts OVD-l andOVU-1 to the junction 236 between contacts 2R-5 and 1R-5.

When the elevator car is stationary at a landing, both relays OVU andOVD are energized, the hand control relay 60H is dropped out when theelevator is on automatic control, the door relay 40R is dropped out whenthe car doors are open, the direction relays IR and 2R are dropped out,and relay ADT is dropped out. Closing pushbutton 232, which is actuatedby maintenance personnel in the machine room when the elevator system isinitially placed in operation, picks up relay CPR via a circuit whichincludes the belt switches 230, contacts OVD-1, OVU-1, and ADT-1.Contact CPR-2 closes to seal in relay CPR and maintain its energizedcondition after the pushbutton 232 returns to its normally opencondition.

When the elevator drive motor prepares to move in the upward direction,the door relay 40R picks up and its contact 40R-1 closes and the updirection relay 1R picks up and contact lR-S closes. As the elevatordrive motor 20 increases its rotational speed. a point is reached whererelay OVU drops out. opening its contact OVU-1. Relay CPR remainsenergized, however. via the closed contacts 40R-1, 60H -1 and lR-S,which shunt the now open contact OVU-l.

When the elevator drive motor rotates in a direction to cause theelevator car to move downwardly, relays 2R and 40R will be picked up toshunt contacts OVD-l with closed contacts 2R-5, 40R-1 and 60H-1. Thus.when the drive motor reaches the speed where relay OVD-l drops out. thecircuit through relay CPR is maintained.

If the car up direction relay IR is picked up but the polarity of themotor armature voltage indicates downward travel. relay OVD will dropout when the motor armature voltage reaches a predetermined magnitude.which is selected to be higher than the motor armature voltage developedduring normal re-leveling. When relay OVD drops out with the updirection relay lR picked up. relay CPR drops out and the elevator carwill make an emergency stop and it cannot be restarted until maintenancepersonnel correct the system malfunction and manually actuate pushbutton232 to again pick up the protective relay CPR.

In like manner. if the down direction relay 2R is energized and relayOVU drops out. indicating the presence of a predetermined motor armaturevoltage magnitude having a polarity indicating rotation ofthe motor forup travel of the elevator car. relay CPR will drop out.

The armature voltage magnitude which will drop out one of the relays OVUor OVD is selected to indicate a motor rotational speed and thus carspeed which is above that at which the doors are set to prc-open. Shouldthe doors pre-open when the motor armature voltage is sufficient todropout either relay OVU or OVD. relay CPR will drop out as contact40R-l will be open. as will contacts OVD-l or OVD-2. and the energizingcircuit for relay CPR will be broken.

When the elevator car is operated on hand control. the hand controlrelay 60H picks up and opens its contact 6OH-1. The maximum car speed onhand control is below the car speed at which OVU or OVD pick up. Shouldthe elevator car exceed this maximum hand control speed and pick up oneof the relays OVU or OVD. relay CPR will drop out and the elevator carwill make an emergency stop.

I claim as my invention:

1. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure toserve said floors.

said motive means including speed control means having first. second andthird modes of operation which control acceleration of said elevator carto first. second and third progressively higher speeds. respectively,

slowdown indicator means disposed in said hoistway for initiatingslowdown of said elevator car at a selected floor.

and notching selector means responsive to runs of said elevator car ofone floor. two floors. and more than two floors. selecting said first.second and third modes of operation. respectively. of said speed controlmeans.

said notching selector means including means for counting at leastcertain of the notchings thereof. with said counting means selecting thesecond ac celerator mode when the elevator car is making a run of twofloors by modifying the effect of said slowdown indicator means.

2. The elevator system of claim 1 wherein the speed control meansincludes energy storage means. with the acceleration of the elevator carduring each of the first. second and third operating modes of the speedcontrol means being responsive to the voltage across said en- (it l ergystorage means. said energy storage means being charged toward the sametarget voltage at the same charging rate for each of the first. secondand third operating modes.

3. The elevator system of claim 2 wherein the slowdown indicator meansincludes at least first and second spaced slowdown indicators disposedin the hoistway associated with each floor for each direction in whichthe elevator car may approach the floor.

and wherein the speed control means includes means for controlling thedeceleration of the elevator car according to the voltage across thesame energy storage means which controls the acceleration of theelevator car. including first slowdown circuit means discharging theenergy storage means towards a first predetermined lower voltage whenthe elevator car passes the first slowdown indicator associated with thefloor at which the elevator car is to stop. and second slowdown circuitmeans discharging the energy storage means towards a sec ondpredetermined lower voltage when the elevator car passes the secondslowdown indicator associated with the floor at which the elevator earis to stop.

4. The elevator system of claim 3 wherein the second slowdown indicatorfor a given floor is located between the first and second slowdownindicators associated with an adjacent floor. and means successivelyenabling the first and second slowdown circuit means. with the timeperiod between the enabling of the first and second slowdown circuitmeans being selected such that the first and second slowdown circuitmeans are responsive to the first and second slowdown indicatorsassociated with the floor at which the elevator car is to stop. whileignoring the intervening second slowdown indicator for the adjacentfloor.

5. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure toserve said floors.

said motive means including speed control means having first. second andthird modes of operation which control the acceleration of said elevatorcar to first. second and third progressively higher speeds.respectively.

notching selector means responsive to runs of said elevator car of onefloor. two floors. and more than two floors. selecting said first.second and third modes of operation. respectively. of said speed controlmeans.

said notching selector means including means for counting at leastcertain of the notchings thereof to determine when the elevator car ismaking a run of one floor. two floors. or more than two floors. controlcircuits for said floors.

means modifying the control circuit of a floor from a first condition toa second condition when the elevator car should stop at this floor.

said notching selector means including means successively enabling thecontrol circuits of said floors responsive to the location and traveldirection of the elevator car.

means responsive to the enabling of the control circuit of the nextadjacent floor to the floor of the last stop of the elevator car whensaid control circuit is in its second condition. for selecting the firstoperating mode.

and means responsive to the enabling of the control circuit of thesecond floor from the last stop of the elevator car. when the controlcircuit of this floor is in its second condition. for selecting thesecond operating mode.

said notehing selector means selecting the third operating mode when theelevator ear does not stop within two floors of its last stop.

6. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure toserve said floors. said motive means including speed control meanshaving first. second and third modes of operation which control theacceleration of said elevator car to first. second and thirdprogressively higher speeds. respectively. said speed control meansincluding energy storage means. with the acceleration of the elevatorcar during each of the first. second and third operating modes of thespeed control means being responsive to the voltage across said energystorage means. said energy storage means being charged toward the sametarget voltage at the same charging rate for each of the first. secondand third operating modes. notehing selector means responsive to runs ofsaid elevator car of one floor. two floors. and more than two floors.selecting said first. second and third modes of operation. respectively.of said speed control means. said notehing selector means includingmeans for counting at least certain of the notehing thereof to determinewhen the elevataor car is making a run of one floor. two floors. or morethan two floors.

first and second voltage clamping means for clamping the voltage acrosssaid energy storage means to voltages corresponding to the maximumoperating speeds of the elevator car for the first and third operatingmodes. respectively. and means maintaining the charging of said energystorage means to a voltage higher than the voltage of the first voltageclamping means. but less than the voltage of the second voltage clampingmeans. for the second operating mode.

7. The elevator system of claim 6 wherein the means maintaining thecharging of the energy storage means to a voltage higher than thevoltage of the first voltage clamping means includes timing means forcontinuing the charging of the energy storage means for a predeterminedperiod of time after the energy storage means has reached the magnitudeof the first voltage clamping means.

8. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator ear mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure toserve said floors.

said motive means including speed control means having first. second andthird modes of operation which control the acceleration of said elevatorcar to first. second and third progressively higher speeds.respectively.

notehing selector means responsive to runs of said elevator car of onefloor. two floors. and more than two floors. selecting said first.second and third modes of operation. respectively. of said speed controlmeans. said notehing selector means including means for counting atleast certain of the notchings thereof to determine when the elevatorcar is making a run of one floor. two floors. or more than two floors.

control circuits associated with each of the floors.

and notehing means successively enabling said control circuits of thefloors in the travel direction of the elevator car in response to theposition of the elevator car relative to the floors.

said means for counting the notchings being responsive to said notehingmeans for determining when the control circuit associated with at leasta second floor from the last stop is enabled by said notehing means.

9. The elevator system of claim 8 including slowdown indicator meansdisposed in the hoistway to signify the slowdown point for each floorwhen the elevator car is to stop at the associated floor. slowdown meansresponsive to the slowdown indicating means of a specific floor when thecontrol circuits of that floor indicate the elevator car should stop atthat floor. and timing means initiated in response to the means forcounting detecting that the control circuit being enabled is associatedwith the second floor from the last stop of the elevator car. saidtiming means delaying the slowdown of the elevator car in the event itis to stop at this floor. notwithstanding the clevator car passing theslowdown indicator means in the hoistway associated with this floor.

10. The elevator system of claim 9 wherein the slowdown indicator meansincludes high and intermediate speed slowdown indicators for each floor.for each direction in which the elevator car may approach the floor. andthe slowdown means includes first and second slowdown means responsiveto the high and intermediate speed slowdown indicators. respcctively.with the maximum speed of the elevator car and spacing of the floorsbeing such that the intermediate speed slowdown indicator for one flooris between the high and intermediate speed slowdown indicatorsassociated with an adjacent floor. and including means delaying theresponse of the second slowdown means to the intermediate speed slowdownindicator once slowdown is initiated by the first slowdown means inresponse to the high speed slowdown indicator. until the interveningintermediate speed slowdown indicator of the adjacent floor has beenpassed by the elevator car.

11. An elevator system comprising:

a structure having a plurality of floors and a hoistway.

an elevator car mounted for movement in the hoistway of said structure.

motive means for moving said elevator car relative to the structure toserve said floors. first and second slowdown indicators spaced in thehoistway for each floor. for each service direction in which saidelevator car may serve the floor.

control means initiating slowdown of said elevator car to stop theelevator car at a predetermined floor in response to the second slowdownindicator for that floor and service direction for a run of one floor.

said Control means initiating slowdown of said elevator car to stop theelevator car at a predetermined evator car to make a two floor run.

12. The elevator system of claim 11 wherein the means which overridesthe first slowdown indicator associated with the stopping floor of a twofloor run, overrides the first slowdown indicator for the second floorfrom the last stop of the elevator car on every run of more than onefloor. regardless of the length of the run.

1. An elevator system comprising: a structure having a plurality offloors and a hoistway, an elevator car mounted for movement in thehoistway of said structure, motive means for moving said elevator carrelative to the structure to serve said floors, said motive meansincluding speed control means having first, second and third modes ofoperation which control acceleration of said elevator car to first,second and third progressively higher speEds, respectively, slowdownindicator means disposed in said hoistway for initiating slowdown ofsaid elevator car at a selected floor, and notching selector meansresponsive to runs of said elevator car of one floor, two floors, andmore than two floors, selecting said first, second and third modes ofoperation, respectively, of said speed control means, said notchingselector means including means for counting at least certain of thenotchings thereof, with said counting means selecting the secondaccelerator mode when the elevator car is making a run of two floors bymodifying the effect of said slowdown indicator means.
 2. The elevatorsystem of claim 1 wherein the speed control means includes energystorage means, with the acceleration of the elevator car during each ofthe first, second and third operating modes of the speed control meansbeing responsive to the voltage across said energy storage means, saidenergy storage means being charged toward the same target voltage at thesame charging rate for each of the first, second and third operatingmodes.
 3. The elevator system of claim 2 wherein the slowdown indicatormeans includes at least first and second spaced slowdown indicatorsdisposed in the hoistway associated with each floor for each directionin which the elevator car may approach the floor, and wherein the speedcontrol means includes means for controlling the deceleration of theelevator car according to the voltage across the same energy storagemeans which controls the acceleration of the elevator car, includingfirst slowdown circuit means discharging the energy storage meanstowards a first predetermined lower voltage when the elevator car passesthe first slowdown indicator associated with the floor at which theelevator car is to stop, and second slowdown circuit means dischargingthe energy storage means towards a second predetermined lower voltagewhen the elevator car passes the second slowdown indicator associatedwith the floor at which the elevator car is to stop.
 4. The elevatorsystem of claim 3 wherein the second slowdown indicator for a givenfloor is located between the first and second slowdown indicatorsassociated with an adjacent floor, and means successively enabling thefirst and second slowdown circuit means, with the time period betweenthe enabling of the first and second slowdown circuit means beingselected such that the first and second slowdown circuit means areresponsive to the first and second slowdown indicators associated withthe floor at which the elevator car is to stop, while ignoring theintervening second slowdown indicator for the adjacent floor.
 5. Anelevator system comprising: a structure having a plurality of floors anda hoistway, an elevator car mounted for movement in the hoistway of saidstructure, motive means for moving said elevator car relative to thestructure to serve said floors, said motive means including speedcontrol means having first, second and third modes of operation whichcontrol the acceleration of said elevator car to first, second and thirdprogressively higher speeds, respectively, notching selector meansresponsive to runs of said elevator car of one floor, two floors, andmore than two floors, selecting said first, second and third modes ofoperation, respectively, of said speed control means, said notchingselector means including means for counting at least certain of thenotchings thereof to determine when the elevator car is making a run ofone floor, two floors, or more than two floors, control circuits forsaid floors, means modifying the control circuit of a floor from a firstcondition to a second condition when the elevator car should stop atthis floor, said notching selector means including means successivelyenabling the control circuits of said floors responsive to the locationand travel direction of the elevator car, means responsive to theenabliNg of the control circuit of the next adjacent floor to the floorof the last stop of the elevator car when said control circuit is in itssecond condition, for selecting the first operating mode, and meansresponsive to the enabling of the control circuit of the second floorfrom the last stop of the elevator car, when the control circuit of thisfloor is in its second condition, for selecting the second operatingmode, said notching selector means selecting the third operating modewhen the elevator car does not stop within two floors of its last stop.6. An elevator system comprising: a structure having a plurality offloors and a hoistway, an elevator car mounted for movement in thehoistway of said structure, motive means for moving said elevator carrelative to the structure to serve said floors, said motive meansincluding speed control means having first, second and third modes ofoperation which control the acceleration of said elevator car to first,second and third progressively higher speeds, respectively, said speedcontrol means including energy storage means, with the acceleration ofthe elevator car during each of the first, second and third operatingmodes of the speed control means being responsive to the voltage acrosssaid energy storage means, said energy storage means being chargedtoward the same target voltage at the same charging rate for each of thefirst, second and third operating modes, notching selector meansresponsive to runs of said elevator car of one floor, two floors, andmore than two floors, selecting said first, second and third modes ofoperation, respectively, of said speed control means, said notchingselector means including means for counting at least certain of thenotching thereof to determine when the elevataor car is making a run ofone floor, two floors, or more than two floors, first and second voltageclamping means for clamping the voltage across said energy storage meansto voltages corresponding to the maximum operating speeds of theelevator car for the first and third operating modes, respectively, andmeans maintaining the charging of said energy storage means to a voltagehigher than the voltage of the first voltage clamping means, but lessthan the voltage of the second voltage clamping means, for the secondoperating mode.
 7. The elevator system of claim 6 wherein the meansmaintaining the charging of the energy storage means to a voltage higherthan the voltage of the first voltage clamping means includes timingmeans for continuing the charging of the energy storage means for apredetermined period of time after the energy storage means has reachedthe magnitude of the first voltage clamping means.
 8. An elevator systemcomprising: a structure having a plurality of floors and a hoistway, anelevator car mounted for movement in the hoistway of said structure,motive means for moving said elevator car relative to the structure toserve said floors, said motive means including speed control meanshaving first, second and third modes of operation which control theacceleration of said elevator car to first, second and thirdprogressively higher speeds, respectively, notching selector meansresponsive to runs of said elevator car of one floor, two floors, andmore than two floors, selecting said first, second and third modes ofoperation, respectively, of said speed control means, said notchingselector means including means for counting at least certain of thenotchings thereof to determine when the elevator car is making a run ofone floor, two floors, or more than two floors, control circuitsassociated with each of the floors, and notching means successivelyenabling said control circuits of the floors in the travel direction ofthe elevator car in response to the position of the elevator carrelative to the floors, said means for counting the notchings beingresponsive to said notching means for determining whEn the controlcircuit associated with at least a second floor from the last stop isenabled by said notching means.
 9. The elevator system of claim 8including slowdown indicator means disposed in the hoistway to signifythe slowdown point for each floor when the elevator car is to stop atthe associated floor, slowdown means responsive to the slowdownindicating means of a specific floor when the control circuits of thatfloor indicate the elevator car should stop at that floor, and timingmeans initiated in response to the means for counting detecting that thecontrol circuit being enabled is associated with the second floor fromthe last stop of the elevator car, said timing means delaying theslowdown of the elevator car in the event it is to stop at this floor,notwithstanding the elevator car passing the slowdown indicator means inthe hoistway associated with this floor.
 10. The elevator system ofclaim 9 wherein the slowdown indicator means includes high andintermediate speed slowdown indicators for each floor, for eachdirection in which the elevator car may approach the floor, and theslowdown means includes first and second slowdown means responsive tothe high and intermediate speed slowdown indicators, respectively, withthe maximum speed of the elevator car and spacing of the floors beingsuch that the intermediate speed slowdown indicator for one floor isbetween the high and intermediate speed slowdown indicators associatedwith an adjacent floor, and including means delaying the response of thesecond slowdown means to the intermediate speed slowdown indicator onceslowdown is initiated by the first slowdown means in response to thehigh speed slowdown indicator, until the intervening intermediate speedslowdown indicator of the adjacent floor has been passed by the elevatorcar.
 11. An elevator system comprising: a structure having a pluralityof floors and a hoistway, an elevator car mounted for movement in thehoistway of said structure, motive means for moving said elevator carrelative to the structure to serve said floors, first and secondslowdown indicators spaced in the hoistway for each floor, for eachservice direction in which said elevator car may serve the floor,control means initiating slowdown of said elevator car to stop theelevator car at a predetermined floor in response to the second slowdownindicator for that floor and service direction for a run of one floor,said control means initiating slowdown of said elevator car to stop theelevator car at a predetermined floor in response to the first slowdownindicator for that floor and service direction for a run of more thanone floor, and means overriding the effect of the first slowdownindicator for a predetermined period of time, for a floor and servicedirection at which the elevator car is to stop for a run of two floors,to delay the initiation of slowdown for the predetermined period of timeand reduce the time required for the elevator car to make a two floorrun.
 12. The elevator system of claim 11 wherein the means whichoverrides the first slowdown indicator associated with the stoppingfloor of a two floor run, overrides the first slowdown indicator for thesecond floor from the last stop of the elevator car on every run of morethan one floor, regardless of the length of the run.